This method ain't gonna change someone to be really patient and forgiving because at some point, the anger will still appear. But at least, the sugar mix in orange juice can make the patience limit looser.
The key ain't in orange juice but on glucose or simple sugar in drinks. In the blood, glucose is sent to the brain as a source of energy, which is also useful to control your temper and other negative emotions.
Lack of supply of sugar to the brain could cause uncontrolled negative emotions, thus becoming more aggressive and irritable. That's why, to certain extent, sweetened orange juice can reduce outbursts of anger.
People with impaired glucose metabolism tend to be more aggressive, such as diabetics. Much sugar is in the blood, but the metabolism is impaired, so it doesn't reach the brain.
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